This is a completely bulls*** ranking.
NO CHINESE CITIES ARE INCLUDED.
There are at LEAST 10 Chinese cities with above 100 PM2.5 concentrations (putting everyone of them on the same level as New Delhi which is number one on the list). It is suspect why China is not on this list.
By comparison, the worst is Bakersfield in the US at 18.
Beijing is listed and it says capitol cities. Each country has 1.
List is of capital cities only.
Bakersfield is not a capitol city.